Five Institutions will join in the proposed Alzheimer's Disease Research Center (ARDC): three Harvard-affiliated hospitals (Massachusetts General, Beth Israel, and McLean Hospitals); the University of Massachusetts Medical Center; and Massachusetts Institute of Technology. This regional consortium will unite a large group of researchers and clinicians with established and potential interests in Alzheimer's disease (AD); it capitalizes on formalized interactions to focus their efforts on improving the diagnosis, understanding the basic mechanisms, and developing treatments for AD. By creating a research capacity and collective intelligence that will exceed the sum of its parts, the Center is designed to cross-fertilize investigations by the exchange of ideas, techniques, and experience. A Clinical Core will enroll, diagnose, and follow an estimated 200 patients with dementia annually, providing a pool of patients for clinical investigation, and systematic clinical data regarding the features of AD. A Data Management Core will store information on all patients in the clinical units and all postmortem examinations in a form facilitating retrieval; it will also assist in protocol design and statistical analyses. A Neuropathology Core will establish diagnoses on all brains obtained, and will operate a brain bank, storing tissue of AD patients suitable for chemical, histologic, histochemical, and immunocytochemical studies. Research projects will examine major issues in AD: new diagnostic methods; reliable information on the clinical course; genetic and biochemical aspects of its etiology; the identity and quantity of neural elements affected; and the biologic basis of clinical manifestations. Through the Harvard Geriatric Educational Center professional training and continuing medical eduation programs will be expanded. A Drug Information Surveillance Center will disseminate information on treatment for AD. Quarterly workshops will engage major scientists to exchange ideas with ADRC members. Together, the Core facilities, scientific projects, and Training and Information Transfer activities will increase the involvement of Massachusetts researchers in AD, and amplify their productivity.